fix: allow older setuptools_scm versions when building

Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>

pyproject.toml

@@ -84,5 +84,5 @@ issue_format = "[#{issue}](https://github.com/pypa/pipx/issues/{issue})"
 package = "pipx"
 
 [[tool.mypy.overrides]]
-module = ["pipx.version", "pycowsay.*"]
+module = ["pycowsay.*"]
 ignore_missing_imports = true

src/pipx/main.py

@@ -28,7 +28,7 @@
 from pipx.interpreter import DEFAULT_PYTHON, InterpreterResolutionError, find_python_interpreter
 from pipx.util import PipxError, mkdir, pipx_wrap, rmdir
 from pipx.venv import VenvContainer
-from pipx.version import __version__
+from pipx.version import version as __version__
 
 logger = logging.getLogger(__name__)
 

src/pipx/version.pyi

@@ -0,0 +1,5 @@
+version: str
+version_tuple: tuple[int, int, int, str, str] | tuple[int, int, int]
+
+# Note that newer versions of setuptools_scm also add __version__, but we are
+# not forcing new versions of setuptools_scm, so only these imports are allowed.